Duplicating block



Nv.13, 1934. c; THYSSEN 1,980,560

DUPLICATING BLOCK Filed June 27, 1951 fly. 2.

Patented Nov. 13, 1934 PATENT OFFICE DUPLICATING BLOCK Gustav Thyssen,Krefeld-Forsthaus, Germany Application June 27, 1931, Serial No. 547,405In Germany October 31,1930

5 Claims.

This invention relates to a duplicating block of alternate superposedwriting sheets with perforated edge and carbon paper sheets boundtogether with the carbon sheets projecting at their edges opposite thebound edge beyond the writing sheets. In the known blocks of this typethe writing and carbon sheets are separated both at the same time fromthe bound edge. In many cases however it is desired to leave the writtensheets, which pass from one department to another attached together bythe bound edge after the carbon sheets have been removed. In the knownblocks it is necessary for this purpose to tear out the carbon sheetssingly, which is troublesome and wastes time. Consequently duplicatingbooks have also been proposed, in which the carbon sheets are insertedloosely between the Writing sheets held together by one glued edge sothat, after the writing of the block, they can be pulled out together.The carbon sheets have an aperture at the top, where they bear againstthe glued edge of the printed form so that abutments remain towards theglued edge which are intended to facilitate the inserting, when buildingup the set. 'I'his object is however only attained in a very imperfectmanner,

' as the weak abutments of the only loosely inserted carbon sheetseasily bend over during their insertion, so that the individual sheetsdo not assume an accurately correct position. A further objection to thecarbon sheets which are only loosely inserted is the possibility ofshiftlng.

In order to avoid these objections, the carbon sheets bound togetherwith the writing sheets of the block are, according to the invention,provided before the binding and perforating with a1- ternating aperturesand spaces along the perforation line so that the carbon sheets are onlyvery loosely attached at their bound edge. The apertures may be formedby holes or by incisions. Carbon sheets thus made may be severedtogether from their bound edge and pulled out of the writing sheets in asingle operation. The carbon sheets according to the invention caneasily be brought into register, when building up the block, as theirbinding edge, extending over the entire width of the block, does notbend over. v

Two embodiments of the invention are illustrated by way of example inthe accompanying drawing in which:-

Fig. 1 shows a carbon sheet in top plan View.

Fig. 2 is a top plan View of a duplicating block.

Fig. 3 is a side view of Fig. 2.

Fig. 4 lis a top plan view of the upper part of a carbon sheet of amodied form of construction.

The carbon block consists of alternately piled up writing sheets a andcarbon sheets b. All the sheets are bound together and perforated alongthe bound edge c. The binding may be effected by glueing or by means ofstaples. The carbon sheets b project at the edge d opposite the bindingedge c slightly beyond the writing sheets a and are cut off diagonallyat one corner at e. The edge d of the carbon sheets is free from carbon,in order not to soil the fingers. Before binding, the carbon sheets bare provided along the perforation line of the binding edge c withconsecutive apertures f or h, arranged at intervals and, after havingbeen united with the writing sheets a, they are again perforated at thesame point with holes g. The apertures may be in the form of holes f(Fig. 2) or incisions h (Fig. 4). Owing to these apertures the hold of75 the carbon sheets b at the binding edge c is so weak that, if theblock is held in one hand at the corner e, they can easily be torn outtogether with the other hand without destroying the holding together ofthev writing sheets a.

I claim:

1. A duplicating block, comprising in combination alternately superposedwriting and carbon sheets bound together and perforated on the bindingedge, said carbon sheets projecting beyond said writing sheets at theedge opposite the binding edge and being cut away along the line ofperforations on the binding edge leaving narrow perforated connectingstrips arranged at intervals apart along the perforationline.

2. A duplicating block as specified in claim 1, in which the cut awayportions are formed by slots extending longitudinally in the directionof the line of perforations.

3. A duplicating block comprising alternately superposed writing andcarbon sheets bound together along one edge and having tearing lines ofperforations inwardly of the bound edge, the tearing lines ofperforations in the carbon sheets being weaker than the perforations inthe writing sheets whereby the carbon sheets may be unitarily severedfrom the block without disturbing the writing sheets.

4. The method of producing a duplicating block consisting of providing aline of cut away portions in carbon sheets, then alternately superposingthe perforated carbon sheets and Writing portions and then perforatngthe sheets of the block on the lines of the cut away portions withperfor-ations occurring in the lands between the cut away portions ofthe carbon sheets to produce tear lines in the carbon sheets weaker thanthe tear lines in the writing sheets.

5. The method of .making a manifold device, comprising the steps ofproviding a sheet of carthe line of the said cut away portions.

GUSTAV THYSSEN.

iso

